Draw out circuit breaker and compartment interlock and secondary contact actuation

ABSTRACT

Drawout switchgear having a truck insertable in a switchboard compartment and a circuit interrupter carrying frame carried by the truck frame and movable toward and away from the back wall of the compartment. Interlock means between the truck frame and the compartment including a hook carried by the truck frame; said interlock means also prevents full insertion of the truck into the compartment when the frame carrying the circuit interrupter is in any position other than a fully withdrawn or test position with respect to the truck frame; and secondary or auxiliary contacts; said interlock means prevent withdrawal of the truck from the compartment when the secondary contacts are engaged; and additional interlock means preventing separation of selected secondary contacts while the circuit interrupter carrying frame is in fully racked in or operative position with respect to stationary disconnect contacts in the compartment.

United States Patent [191 Wilson [451 Feb. 19, 1974 [75] Inventor: George A. Wilson, Pineville, Pa.

[73] Assignee: ITE Imperial Corporation,

Philadelphia, Pa.

[22] Filed: Aug. 21, 1972 [21] Appl. No.: 282,330

Primary Examiner-J. R. Scott Attorney, Agent, or Firm-Ostrolenk, Faber, Gerb & Soffen 5 7 ABSTRACT Drawout switchgear having a truck insertable in a switchboard compartment and a circuit interrupter carrying frame carried by the truck frame and movable toward and away from the back wall of the compartment. Interlock means between the truck frame and the compartment including a hook carried by the truck frame; said interlock means also prevents full insertion of the truck into the compartment when the frame carrying the circuit interrupter is in any position other than a fully withdrawn or test position with respect to the truck frame; and secondary or auxiliary contacts; said interlock means prevent withdrawal of the truck from the compartment when the secondary contacts are engaged; and additional interlock means preventing separation of selected secondary contacts while the circuit interrupter carrying frame is in fully racked in or operative position with respect to stationary disconnect contacts in the compartment.

6 Claims, 44 Drawing Figures PATENIEDEBI 91m sum 01 or 21 PATENTEBFEBI 91914 SHEET 02 n; 21

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1. In draw out switchgear having a housing; said housing having a substantially open side and a wall parallel to and opposite said open side; said switchgear having a first frame and a second frame reciprocally mounted with respect to said first frame; said second frame carrying circuit interrupter elements and back connection contacts; complementary connectors for said back connection contacts in said wall of said housing; said back connection contacts being engageable and disengageable with said complementary contacts; said switchgear being introduceable into said housing through said open side; means for securing said first frame with respect to said housing; said second frame being movable with respect to said first frame, when said first frame is secured, between a position in which said back connection contacts engage said complementary contacts and a position in which they are disengaged; said first frame being locked in position in said housing in any position of said second frame with respect to said first frame other than the disengaged position of said back connection contacts with respect to said complementary contacts; said securing means comprising a hook rotatably carried on said first frame and lying in a plane parallel to the path of movement of said switchgear through said open side of said housing; a detent on said hook; a projection in said housing engaging said detent when said switchgear is fully introduced into said housing; means for locking said hook into a position in which its end will abut said projection and prevent full introduction of the switchgear into said housing when the second frame is in any position with regard to said first frame other than the position of said second frame in which said back connection contacts are withdrawn with said second frame toward said first frame.
 2. The draw out switchgear of claim 1, having also secondary contacts comprising stationary contact members carried by said housing and movable contact members carried by said first frame; means for actuating said movable secondary contacts between engagement and disengagement position; and an interlock for said movable secondary contact members; said interlock engaging said actuating means for said secondary contacts and blocking said actuating means from operating selected secondary contacts from disengaging said stationary secondary contacts when the second frame is in a position in said housing in which the back disconnect contacts engage their complementary contacts; said interlock in addition blocking said hook from movement to a position in which said detent may disengage said projection, when the second frame is in a position with respect to the first frame with the back disconnect contacts fully disengaged, while the remainder of the secondary contacts are engaged.
 3. The draw out switchgear of claim 2 in which: said movable secondary contacts are mounted on a slide carried By said first frame; said stationary contacts comprising a first set of stationary contacts and a second set of stationary contacts on the housing off-set with respect to each other; movement of said slide from a first full disconnect position to a second partially connected position engaging said movable contacts with one said set of said stationary secondary contacts; movement of the slide to a third position engaging the movable contacts with both sets of stationary contacts.
 4. The draw out switchgear of claim 3 in which: a projection extends from said hook into a recess in said slide; the engagement of said hook projection with said recess preventing rotation of said hook; the said hook projection being disengaged from said recess when said slide is in said first full disconnect position of all the said secondary contacts.
 5. The draw out switchgear of claim 4 having: means for operating said circuit interrupter elements including a trip member; said trip member being positioned to initiate the operation of said current interrupter elements to switchgear open position; a connection from said slide to said trip member; said connection operating said trip member on initiation of movement of said slide toward a position in which said secondary contacts are disengaged.
 6. The draw out switchgear of claim 5 in which said connection maintains said trip member in position to cause said circuit interrupter elements to remain in switchgear open position while said slide is in disconnected position. 